Respiration

polar bears are mammals so they have lungs, veins, blood, heart, and arteries. the arteries transport the oxygen around he body and breathe out the carbon dioxide.

Fun Fact: polar bears can close off there nose when swimming so no water can get in.

                                   circulation

polar bears have a closed circulatory system. polar bear blood cells have adapted to store more oxygen for when they are underwater so they can breathe longer. their blood vessels have adapted to dilate with the more blood which lets the bear stay in the cold water longer

                                Digestion                                   

the Bears digestive system absorbs about 84% of the protein and 97% of the fat.

It takes 20 hours for a polar bear to digest food

there stomachs are very expandable and can hold 15-20% of their body weight at a time

                                   nutrients

The bear uses their strong jaws to chew seal meat and other fish. 

after that they swallow the chewed food and it goes down their esophagus and starts the digestive process

                        Food gathering

The polar bears get their food by hunting seals by waiting near holes they come up from to get water and drag them onto the land. 

They are carnivores so they also hunt walruses and dead whale carcasses they find

                                       Support

Some adaptations are their white fur. they use this as a form of camouflage. they have a very thick layer of fur to endure the cold temperatures

                                   Protection

The polar bears thick skin of fur helps protect itself from the cold temperatures of Antarctica. they also have a greasy coat that sheds water after swimming to help reduce heat loss.

                               Movement

Like humans polar bears have plantigrade stance which means they stand on the heels of their feet. they can also stand up on their two hind legs as a tactic to scare animals off

Osmotic regulations

During hibernations the bears can go 6-8 months without eating, drinking, urinating, and defecating. they create their own water from metabolizing fat stored in their body.

Temperature regulation

Polar bears are endotherms. This means that animals can generate heat internally to keep their body warm

Reproduction

The polar bears reproduce sexually during the spring and the females give birth in the winter. They usually give birth to twins and stay with the mother up to 28 months after their birth

Development standards

While the baby is in the maternity den it starts to develop and grow. Two months after birth the cub with start to be able to walk, grow thicker skin, and teeth start to emerge. Polar bears can live up to 30 years with the oldest recorded living to 42.

mating behaviors

Polar bears have mock fights to initiate play with their cubs for fun they do this by standing on their hind legs